.box {
    width: 100%;
    height: 100vh;
    display: flex;
}
.left{
    width: 30%;
    height: calc(100vh-"30px");
    overflow-y: auto;
    background-color: antiquewhite;
}
.right{
    width: 70%;
    height: calc(100vh-"30px");
    overflow-y: auto;
    background-color: aqua;
}

.left {
    width: 30%;
    height: calc(100vh - '30px');
    overflow-y: auto;
    background-color: orchid;
}

.right {
    width: 70%;
    height: calc(100vh - 30px);
    overflow-y: auto;
    background-color: chartreuse;
}

.left div {
    width: 100%;
    height: 60px;
    line-height: 60px;
    text-align: center;
}

